miR-141-3p Enhanced Radiosensitivity of CRC Cells

BACKGROUND

Colorectal cancer (CRC) is recognized as one of the frequently diagnosed malignancies, and numerous microRNAs (miRs) are identified to be active in CRC.

OBJECTIVE

This work aimed to clarify the effect of miR-141-3p on the radiosensitivity of CRC cells.

METHODS

Firstly, CRC cell lines were cultured and applied to construct radiation-resistant CRC cells via X-ray treatment. The expression levels of miR-141-3p and long non-coding RNA DLX6 antisense RNA 1 (lncRNA DLX6-AS1) in CRC cells were measured using real-time quantitative polymerase chain reaction. After transfection with miR-141-3p mimics and 24 h treatment with 6- MV X-ray (0, 2, 4, 6 Gy), the survival fraction (SF) and the colony formation ability of CRC cells were determined using the cell counting kit-8 and colony formation methods. The interactions between miR-141-3p and DLX6-AS1 were analyzed using the dual-luciferase assay. The impact of miR-141-3p on DLX6-AS1 stability was detected after adding actinomycin-D. The role of DLX6- AS1 in the radiosensitivity of CRC cells was explored by transfecting oe-DLX6-AS1 into radiation- resistant CRC cells overexpressing miR-141-3p.

RESULTS

The relative expression levels of miR-141-3p were downregulated in CRC cells and further declined in radiation-resistant cells. Upregulation of miR-141-3p relative expression reduced SF and the colony formation ability while amplifying the radiosensitivity of radiation-resistant CRC cells. miR-141-3p directly bound to DLX6-AS1 to reduce DLX6-AS1 stability, and therefore downregulated DLX6-AS1 expression. DLX6-AS1 overexpression counteracted the role of miR- 141-3p overexpression in amplifying the radiosensitivity of radiation-resistant CRC cells.

CONCLUSION

miR-141-3p binding to DLX6-AS1 significantly decreased DLX6-AS1 stability and expression, promoting the radiosensitivity of CRC cells.

Factors affecting pathological response and survival following neoadjuvant chemoradiotherapy in rectal cancer patients

Background

Despite all advanced treatment methods for rectal cancer, not all patients can provide an adequate response, and hence, possible prognostic factors must be evaluated. The aim of this study was to evaluate the relationship between systemic inflammatory markers and pathological response, overall survival (OS) and disease-free survival (DFS) in patients treated with neoadjuvant chemoradiotherapy (nCRT).

Methods

We evaluated data of 117 patients for the period 2010 to 2017. Serum measurements of albumin, hemoglobin, C-reactive protein, modified Glasgow prognostic score (mGPS), and white cell counts were obtained. Rodel scoring system was used to determine pathologic tumor regression.

Results

Overall, 77% of the patients were in the good response group according to the radiological images. A total of 48% of patients were categorized as a good pathologic response. Pathologic response to treatment was associated with a mGPS of 0 (P = 0.001), normal platelet lymphocyte ratio (PLR) (P = 0.003), TNM stage (P = 0.03), pathologic T stage (P = 0.001), radiologic response to nCRT (P = 0.04), tumor differentiation (P = 0.001), lymphovascular invasion (LVI) (P = 0.001) and perineural invasion (P = 0.02). LVI (P = 0.04), albumin level (P = 0.05), C-reactive protein (P = 0.01), neutrophil platelet score (NPS) (P = <0.001) and mGPS (P = 0.01) had a statistically significant effect on OS. Operation type (P = 0.03), tumor differentiation (P = 0.01), depth of invasion (P = 0.03), NPS (P < 0.01), mGPS (P = 0.01), PLR (P = 0.004), neutrophil-lymphocyte ratio (P = 0.01) and LVI (P = 0.05) were statistically significant on DFS.

Conclusions

There was an association between systemic inflammatory markers and pathologic response and also, between OS and DFS. This study can be preliminary data for prospective controlled studies.

High Immunoreactivity of DUOX2 Is Associated With Poor Response to Preoperative Chemoradiation Therapy and Worse Prognosis in Rectal Cancers

Purpose: Colorectal cancer is the third most common cancer and also the fourth most common cause of cancer mortality worldwide. For rectal cancer, neoadjuvant concurrent chemoradiotherapy (CCRT) followed by radical proctectomy is gold standard treatment for patients with stage II/III rectal cancer. By data mining a documented database of rectal cancer transcriptome (GSE35452) from Gene Expression Omnibus, National Center of Biotechnology Information, we recognized that DUOX2 was the most significantly up-regulated transcript among those related to cytokine and chemokine mediated signaling pathway (GO:0019221). Hence, the aim of this study was to assess the DUOX2 expression level and its clinicopathological correlation and prognostic significance in patients of rectal cancer.

Materials and Methods: DUOX2 immunostain was performed in 172 rectal adenocarcinomas treated with preoperative CCRT followed by radical proctectomy, which were divided into high- and low-expression subgroups. Furthermore, statistical analyses were examined to correlate the relationship between DUOX2 immunoreactivity and important clinical and pathological characteristics, as well as three survival indices: disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS).

Results: DUOX2 overexpression was linked to post-CCRT tumor advancement, pre- and post-CCRT nodal metastasis and poor response to CCRT (all P ≤ 0.021). Furthermore, DUOX2 high expression was significantly associated with inferior DSS, LRFS and MeFS in univariate analysis (P ≤ 0.0097) and also served as an independent prognosticator indicating shorter DSS and LRFS interval in multivariate analysis (hazard ratio (HR) = 3.413, 95% confidence interval (CI): 1.349-8.633; HR = 4.533, 95% CI: 1.499-13.708, respectively).

Conclusion: DUOX2 may play a pivotal role in carcinogenesis, tumor progression and response to neoadjuvant CCRT in rectal cancers, and serve as a novel prognostic biomarker. Additional researches to clarify the molecular and biochemical pathways are essential for developing promising DUOX2-targeted therapies for patients with rectal cancers.

Overexpression of Transcobalamin 1 is an Independent Negative Prognosticator in Rectal Cancers Receiving Concurrent Chemoradiotherapy

Objective: Neoadjuvant concurrent chemoradiotherapy (CCRT) is an increasingly common therapeutic strategy for locally advanced rectal cancer, but stratification of risk and final outcomes remain a major challenge. Transcobalamin 1 (TCN1), a vitamin B12 (cobalamin)-binding protein, regulates cobalamin homeostasis. High expression of TCN1 have been reported in neoplasms such as breast cancer and hepatocellular carcinoma. However, little is known about the relevance of TCN1 to rectal cancer receiving CCRT. This study examined the predictive and prognostic impact of TCN1 expression in patients with rectal cancer following neoadjuvant CCRT. Methods: Through data mining from a published transcriptome of rectal cancers (GSE35452), we identified upregulation of TCN1 gene as the most significantly predicted poor response to CCRT among ion transport-related genes (GO:0006811). We evaluated TCN1 immunohistochemistry and performed an H-score analysis on endoscopic biopsy specimens from 172 rectal cancer patients receiving neoadjuvant CCRT followed by curative surgery. Expression levels of TCN1 were further correlated with clinicopathologic features, therapeutic response, tumor regression grade (TRG) and survivals including metastasis-free survival (MeFS), disease-specific survival (DSS) and recurrent-free survival (LRFS). Results: TCN1 overexpression was significantly related to advanced post-treatment tumor (T3, T4; p<0.001) and nodal status (N1, N2; p<0.001), vascular invasion (p=0.003) and inferior tumor regression grade (p < 0.001). In survival analyses, TCN1 overexpression was significantly associated with shorter DSS (p<0.0001), MeFS (p=0.0002) and LRFS (p=0.0001). Furthermore, it remained an independent prognosticator of worse DSS (p=0.002, hazard ratio=3.344), MeFS (p=0.021, hazard ratio=3.015) and LRFS (p=0.037, hazard ratio=3.037) in the multivariate comparison. Conclusion: Overexpression of TCN1 is associated with poor therapeutic response and adverse outcomes in rectal cancer patients receiving CCRT, justifying the potential prognostic value of TCN1 in rectal cancer receiving CCRT.

High Expression of Aldolase B Confers a Poor Prognosis for Rectal Cancer Patients Receiving Neoadjuvant Chemoradiotherapy

Background : Colorectal cancer is the third most common cancer in both sex worldwide and it is also the fourth most common cause of cancer mortality. For rectal cancer, neoadjuvant concurrent chemoradiotherapy (CCRT) followed by radical proctectomy is gold standard treatment for patients with stage II/III rectal cancer. By data mining a documented database of rectal cancer transcriptome (GSE35452) from Gene Expression Omnibus, National Center of Biotechnology Information, we recognized that ALDOB was the most significantly up-regulated transcript among those related to glycolysis (GO: 0006096). Hence, we analyzed the clinicopathological correlation and prognostic effect of ALDOB protein (Aldolase B), which encoded by ALDOB gene. Methods : ALDOB immunostain was performed in 172 rectal adenocarcinomas treated with preoperative chemoradiotherapy followed by radical surgery, which were divided into high- and low-expression groups. Furthermore, statistical analyses were examined to correlate the relationship between ALDOB immunoreactivity and important clinical and pathological characteristics, as well as three survival indices: disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS). Results : ALDOB (Aldolase B) over-expression was significantly associated with pre-CCRT and post-CCRT tumor advancement, lymphovascular invasion, perineural invasion and poor response to CCRT (all P ≤ .023). In addition, ALDOB high expression was linked to adverse DSS, LRFS and MeFS in univariate analysis (P ≤ .0075) and also served as an independent prognosticator indicating dismal DSS and MeFS in multivariate analysis (hazard ratio (HR) = 3.462, 95% confidence interval (CI): 1.263-9.495; HR = 2.846, 95% CI: 1.190-6.808, respectively). Conclusion : ALDOB (Aldolase B) may play an imperative role in rectal cancer progression and responsiveness to neoadjuvant CCRT, and serve as a novel prognostic biomarker. Additional researches to clarify the molecular and biochemical pathways are essential for developing promising ALDOB-targeted therapies for patients with rectal cancers.